Sheep shear



Dec@ 1 F. G. W. BRISTOW SHEEP SHEAR Filed June 4, 1923 Patented Dec. 1, 1925.

FRANCISS GEORGE WILLIAM BRISTOW,

OF SYDNEY, AUSTRALIA, ASSIGNUR TO CHICAGO FLEXIBLE SHAFT COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION )F ILLINOIS.

SHEEP SHEAR.

Application filed June 4,

To all whom t may concern.'

Be it known that I, FnANcIss Gnonen W'n.- LrAM Buis'row, a subject of the King of Great Britain, and a resident of Sydney, Australia, have invented certain new and useful Improvements in Sheep Shears, of4 which the following is a specification, refer ence being had to the accompanying drawings, forming a part thereof.

The purpose of this invention is to provide an improved construction of power-operated sheep shear in which the pressure for holding the co-operating shear members in proper contact with each other for shearing does not reactv on the bearings of the operatt ing lever, and in which accommodation is aiorded for lack of parallelism between the plane 0f operation of the operating lever and that of the fixed cutter and comb, which may occur from distortion of the parts arising in continuous use. It consists in the elements and features of construction shown and described, as indicated in the claims.

In the drawings:

Figure l is a fore and aft section of a sheep Yshear embodying this invention.

Figure 2 is a top plan view of the same with the cover plate and tension rod or dolly7 removed.

of the structure shown in Figure l showing a modification in respect to the pivoting of the pressure member.

Figure L is a view similar to Figure l showing another modification. y

Figure 5 is a detail showing a modification in respect to the yielding step for the tension rod of the general character shown in Figure 4.

Figure 6 is a detail section showing a modified form of the tension rod, for dispensing with the yielding step bearing for that part which is shown in Figures 4t and 5.

Figure 7 is a perspective view of a yoke or Spanner desirably employed in embodying this invention in existing types of sheep shears.

Figure 8 is a plan view of the vibrating cutter.

The structure shown in the drawings comprises the customary base frame and handle member, A, of a sheep shear having secured to it in customary manner the fixed comb and cutter, B, and pivotally mounted in it the operatingk lever, C, yfor the vibrating Figure 3 isa detail section of a portion 1923. serial No. 643,156.

cutter, E, said lever being driven by a crank wheel, l), on the end of the power shaft, E. rlhe lever, C,l is engaged with the vibrating cutter, E, by means of downwardly-projecting studs, c, mounted in the terminal lingers of the lever, entering holes, el, in the cutter, E; so that the vibrating cutter is vfree for up-and-'down movement relativelyv to the lever which operates it, that is, so that the operating lever for vibrating the cutter is not relied upon for pressure to hold the vibrating cutter to the comb and fixed cutter, B. The pressure for holding the co-operating cutter members together is applied by means of a pressure member, F. This pressure member is pivoted for swinging about the pivotal axis of the operating lever so that it follows perfectly the movement which the vibrating cutter derives from that lever; and it is also pivotally mounted for vertical movement to apply pressure to the vibrating cutter. This pressure member is also constructed and supplied with pressure means so that the pressure which it applies to the vibrating cutter is yielding to a suiiicient extent to make it possible to press the two cutters together with certainty of producing eiiective contact between them for shearing,

`together under conditions of use. For the purpose of adapting the pressure member for pivotal movement about the axis of the lever, and also for pivotal movement in a vertical plane, and for the purpose of applying such pressure member to existing types of sheep shears in whose present construction the pressure upon the vibrating cutter is exerted directly by the operating lever, the construction shownin Figures l and 2 may be em* ployed. In this construction there is provided a threesided yoke or spanner member J, adapted to clasp the lever, C, at its pivot, the middle side of the spanner having an aperture, y', for tting onto the pivot stud, h, of the lever, C, under the lever the two sides extending up at opposite sides of the lever and projecting there-above for engaging between them thepivotal cross-head, F1, of the pressure member, F, the yoke or Spanner being made of springV material so that the two sides may be sprung apart to admit said pivotal cross-head between them and engage its pivotal terminals as seen in `Figure 2.

The customary tension rod or dolly, L,

stopped at its upper end by the adjustable cap, A5, bears at its lower end in a suitable step bearing. provided in the upper side of the pressure member, F. In order that the pressure member may accommodate itself to the vibrating cutter so as to apply pressure equally at seve al points ot its pressure thereon, even in the case ot some distortion of the parts which may occur in use, ausing the plane of vibration of the operating level', C, to be out of parallel with the plane ot the comb and fixed cutter, B, it is advantageous to have the pressure member mounted pivotally, not only for vertical movement, but also for rocking movement about a fore-andatt axis in a vertical plane; and for this purpose' in the t'orm shown in Figuresl and 2, the pivotal cross-head, F1, is made as a separate piece from the main body of the pressure member, F, and the latter at its rear end terminates in a short pivotal stem, f1, for which' pivotal bearingis made crosswise ot the cross-head,vF1, the pivotal stem, f1, extending beyond the cross-head and receiving a cotter pin, f2, tor retaining the two parts together.

In this construction it is contemplated that the shank or main longitudinal extent ot the pressure member, F is thinenough and ot such material as to have the necessary elastic reactionso that the vibrating cutter is pressed i,f'ieldingly and not with absolute rigidity upon the comb and fixed cutter, B. In' Figure 3 there is shown a modification ot the pivotal support. for ther pressure member, F, which may be adopted' when the tool is originally constructed in accordance with this'invention, the form shown in Figures l and 2 being as stated, designed for applying the present invention to existii'ig tools originally constructed without it. In this form shown in Figure 3', the stud, H, which constitutes the fulcrum of the operating lever, C, being rigidly secured at its lower end in the base trame, A, projects up through the lever and its upper end is bored and tapped for screwing into it a pivot seat, G, for the pressure member.` This pivot seat comprises a flange which is ot greater diameter than the tulcrum stud, H, so that under it and abovethe lever there may be placed alight coiled spring, M, which without applying any substantial pressure for increasing the friction ot the lever, renders itanti-rattling on the fulcrum stud. The upper side of the seat, has a conical socket, g, which seats a conical pivot boss, f2,

which'is formed projecting downward from the rearend of the pressure member, F, the angle ot. the conical boss being less than the angle ot the conical socket, so that the pressure member, F, is free tov rockin all directions as it the joint were spheroidal, thus p1'`ov'idir1gl both for the vertical pivotal movement by means of which the pressure member may apply Vpressure to the vibrating cutter, and also for the rocking about a toreand-att axis in a vertical plane by which the pressure member may accommodate itself to lack ot parallelism betweenthe plane of vibration of the operating lever and the plane ot the fixed cutter and comb. It will be understood that this construction shown in Figure 3 is intended to serve the same purpose in respect to the different pivotal movements which is served in the different constructions shown in Figures l and 2 by the pivoting of the cross-head, F1, transversely in the yoke, G, and pivoting the body ot the pressure member longitudinally in said cross-head.

In Figure et there is shown a modification for the purpose of providing the elastic reaction 0f the pressure member without reliance upon the elasticity ot that member itself, thus permitting said member to be made more rigid' than it would be desirably made in the form shown in Figures l, 2 and 3. In this form shown in Figure 4, the pressure member FX, is or may be ot heavier construction as to the shank than shown in previous figures, and in this shank there' is mounted a cup or socket member, T, in which a step bearing, T1, for thelower end ot the tension rod or dolly, L, is mounted tor vertical movement, a coiled spring, T2, being provided around the stem, t1, ot the step, Tl, for yieldingly upholding said step, said stem, t1, being of such length that at the normal adjustment of the parts in service it is stopped at the bottom ot the cup, the spring being under compression at this normal adjustment. A check bracket, T3.A is shown mounted upon the upper side of? thc pressure member engaging the neck oitl the tension rod above the bearing terminal. thereoft to prevent accidental displacement which might occur during assemblage or adjustment ot the upper stop bearing, A5, ot the tension rod. In this construction the normal adjustment of the upper stop, A, of thc tension rod beingmade by screwing in tight,-that is, until the stem, t1, ot the step, Tl, is stopped at the bottom ot the cup, T, the pressure which will be thereby applied to the pressure member will be yielding to the extent ot the range ot further con'ipressibility o'l' the spring, for it will be evident that in tact the pressure member will have been forced downward by the adjustment ot the upper stop, A5, only by the reaction ot the spring against the bottom of the cup until the stem, t1, reached the bottom of the cup; and it is contemplated that this spring will be otvsuch stiffness that the pressure `which it will apply thus yieldingly will be adequate for holding the co-operating cutters in edective contact for theirshearingtunction,

VFigure 5 shows a slight modification in the form of the cupped step bearing described, the modification consisting in extending a central stem, 1510, up from the bottom of the cup to reach and stop the step bearing, T1, instead of extending the stem,

tl, down from the step bearing to reach 'the bottom of the cup. The operation will be obviously the same as in Figure 1.

In Figure 6 there is shown another modification in which the spring for affording elastic reaction to the pressure-applying means is embodied in the tension rod which is made of two members, L1, and L2, telescoped with each other and having the inner member, L2', axially chambered for accommodating a coiled spring, L3. It will be obvious without explanation that the combination of this construction will be the same, so far as giving yieldingness to the pressure upon the cutter, as those shown in Figures 4L and 5. It will be understood that the construction for yieldingness in which an independent spring is employed, as in Figures 4, 5 and 6, may be embodied either with the form of pivotal mounting of the operating lever and pressure member shown in Figures 1 and 2, or with that shown in Figure 3. And the showing of the same shown in conjunction with the yform shown in Figure 2 is not to be understood as limiting its use to that form.

I claim 1. In a sheep shear and the like, in combination with a rigid comb-carrying frame structure and a comb carried thereby, a vibrating cutter; a cutter-actuating lever having a fixed fulcrum on the frame structure and engaging the cutter for vibrating the latter; a pressure member for holding the cutter to the comb, engaged at one end with the cutter independently of the cutter-'actuating lever, and at the other end pivoted to the frame structure independently of said cutter-actuating lever; and a thrust member for applying pressure to the pressure member, stopped in one direction on the pressure member and in the opposite direction on the iframe and in both said stoppages, being independent of the cutter-actuating lever; whereby the pressure .for holding the cutter to the comb is transmitted to the cutter independently of the cutter-actuating lever.

2. In a sheep shear and the like, in combination with a comb-carrying frame structure and a comb carried thereby, a vibrating cutter; pressure-transmitting means for holding the cutter yon the comb, comprising a pressure member pivoted to the frame and engaging the cutter, a thrust member and a stop therefor in one direction of its thrust on itsv frame, said thrust member being stopped in the opposite direction on the pressure member; and a cutter-actuating lever fulcrumed on the frame and engaging the cutter, said lever being free from any pressure transmitted through the thrust member.

3. In the construction defined in claim 2, an elastically reacting part comprised in the pressure-transmitting means interposed between the stop on the frame and the cutter, said stop on the frame being adjustable substantially in the direction of thrust to vary the pressure transmitted.

4L. In the construction defined in claim 2, a resilient part comprised in the pressuretransmitting means, and means for tensioning said resilient part.

5. In the construction defined in claim 1 foregoing, the fixed fulcrum of the cutteractuating lever having mounted upon it a fixed fulcrum for the pressure member.

6. In the construction defined in claim 1 foregoing, a yoke adapted to be mounted on the fixed fulcrum of the cutter-actuating lever spanning said lever and extending there-above for affording above the lever a fulcrum for the pressure member independent of said lever with the axes of said two fulcra intersecting each other.

7. In a sheep-shearing tool and the like, in combination with a comb-carrying base frame and the comb carried thereby, a reciprocating cutter; a cutter-actuating lever engaged with the cutter with freedom for relative movement between them in the direction transverse to that of the cutters reciprocation; pivotally mounted pressure means having` its fulcrum support on the base frame and comprising an elastically yielding part, and a thrust member for directing the pressure onto the vibrating cutter and adjustable means for tensioning the elast-ically yielding part of the pressure means.

S. In the construction defined in claim 7, foregoing, the pressure member being pivoted for rocking about a fore-and-aft axis as Well as for swinging about a vertical axis with the reciprocation of the cutter.

In testimony whereof I have hereunto set my hand at Chicago, Illinois, this 25th day of May, 1923.

FRANCISS GEORGE WILLIAM BRISTOW. 

